Question about Old Earth Stove Air Intake

[Blazzinghot]

Hi, I have another project I am working on. I went to the recycle steel yard and this wood stove was sitting right there for the taking at 20 cents a lb. It was less than $80.00 as I had to also pay for the weight of the bricks. I did complain but to no avail. I am not wanting to identify this stove as I found some info on it from searching the internet. But what I can't find is how the coil works to adjust the air intake on the back side of the stove. This stove still has the coil which was connected to the rod hooked to the flapper on the back. But everything else is gone. I know this is a long shot but was hoping someone might still have one of these Earth Stoves and could send me a picture of how the bio-metric coil hooks up on the back.

Is someone with a sharp eye might notice that this stove have a handle on it on the right side it is because this is the Earth King as I put a damper inside.

The box on the back of the stove is homemade. But you can see how the coil is just hanging out in the open. I did attach a knob with a spring tension but not sure I did the right thing. Hope someone can help with this. Thanks

 

[coaly]

The model 100 had a 3 position knob / lever that tightened and loosened the bimetallic spring that was connected to a rod that went down to door flapper. It should of course be fully open when cold and adjust to close at desired low temp, like 250 on pipe thermometer, 300 medium, 350 -400 high. With it cold, you should be able to close the damper flap by hand, pulling the spring tighter. As long as you can close the flap it's safe to start and adjust from there. You may have to put a weight on the flap like a clamp or vice grips to hold it shut enough to prevent overheating until you get it right. I don't know what friction device they use to keep the knob in position. That shaft must be held in position so the spring moves the rod and flap, not adjuster shaft. May have had detents on the lever, other t-stats by others have a friction control inside to prevent the control shaft the spring is mounted on from rotating out of the set position.

Friction control on left.

 

[Blazzinghot]

coaly, Thanks for the picture and your comments. When I built the box for to hold the knob and to fasten the bimetallic spring. I welded a small nail to the inside of the metal box on the outside part of the bimetallic spring as the other end is already attached to the rod as shown in the picture. I set in in position so that the flapper was fully opened. When I fired up the stove as soon as the stove heated up the bimetallic spring closed the air intake flap. I have a spring for tension on the knob shaft but it was not strong enough to hold open the air intake flap. What you said about the friction device is my problem.

When you say three positions for the heat control does the knob click or can you feel it snap into each position?

I might have to dream up some other ideas. I believe this stove is a 101 as it has the round ceramic tile on the front.

 

[coaly]

I don't think any of them clicked in place. But it has to remain in place to make the flap move instead of the shaft turning. A Dual Heat used by Hitzer has a gear reduction from the turn knob shaft to the shaft connected to spring. That way as you rotate the knob the movement of the secondary shaft is very little and doesn't turn the knob shaft easily. Never took one like yours apart. Maybe just a spring with a loop around the shaft pulling sideways to prevent it from rotating freely? If the loop or hook on the end of a spring isn't enough, due to very little contact on the shaft causing friction, a wider area like a pipe strap made into a loop around the shaft will increase friction preventing easy rotation. Just don't lubricate it. They are a simple mechanical device. European stoves use an oil filled capillary system with dampers and dashpots that are much more accurate, but like the rest of the European stoves are far more complicated.

 

[Blazzinghot]

Thanks again for your thoughts. I am learning allot working on these stoves. With you discussing this helps me to dream up some other ideas.

 

[Blazzinghot]

Just wanted to post an update on this Earth Stove. I call it the Earth King because I put a damper inside like what was in the Blaze King, I posted on this forum some time back. I dreamed up an idea for a combustor so tried it out on this Earth Stove. I did not mention it earlier as did not have cold enough weather to put my newly designed stove to the test. It was rainy morning so I fired up the Earth King and ran it most of the morning until the sky cleared up. The combustor is made out of perforated stainless-steel sheeting. I think it is 20 gauge not sure what size the holes are. The picture shows my set up before I welded it inside the stove. It measures 2 inches by 8 inches and is designed to unbolt just in case it didn’t work. There is about 10 layers of these small panels with spacers between each layer for better air exchange. (see picture) Inside the wood stove I welded a ¼ plate about an inch above the combustor so it would spread the heat rather then get the top of the stove to hot. Again, this idea comes from the Blaze King. There is also a secondary burn tube set up before the fire goes into the combustor.
Today I was able to burn a few small logs with some scrap pine lumber for about 5 hours this morning. When my homemade combustor started working, I would get white smoke and sometimes no visible smoke from the stack. The stove ran at an even 350 to 400 degrees for about two hours until it needed a few more pieces of wood. The wood stove was putting out a nice even heat. I don’t know how long the combustor will last but the stainless steel should last for a long time. I would like to try this again using ¼ inch hole perforated stainless-steel sheeting.

 

[coaly]

You're probably seeing steam, not smoke. Tremendous amount of water vapor formed from combustion.

 

[BKVP]

Two matters to consider.

1) Manufacturer clearances will not apply because of the modifications made to the stove. So, if you are able to get it back to the original specs, you can comfortably use the clearances to combustible in the original manual. I did run across a shop in TN that had lots of old Earth Stoves on display (historical) and I did not ask if they had any parts. You can send me a PM if you want the contact info,

2) Be careful on the rationale behind having heavy steel plates near the front of rear faces of the combustor. Excessive heat will destroy the wash coat with excess temps, essentially removing the precious metals and wash coat applied to the metal substrate. And just because the substrate does not collapse (metal vs ceramic), once the wash coat exceeds 1600F, the goal of the combustor is defeated.

Good luck, be safe!

 

[Blazzinghot]

BKVP, thanks for sharing our concerns. I posted this update about my homemade combuster because it always brings in other info which might help me in the future. I have the stove in my garage and only need to worry about the clearance on the back side. I think I have about 20 inches of clearance with corrugated metal sheeting screwed to the sheet rock. But I am going to change this so it has some space between the metal an the Sheetrock so that air can flow between the two surfaces.

I put 1/4 plating about an inch above my homemade combustor to protect the top of the wood stove. I will find out more when winter comes as stove season is pretty much over here in my area. The Blaze King I had with the combustor had very thing steel plate above the combuster so was thinking 1/4 is better. Plus I had some sheeting left over from working on other stoves. I will try to keep an eye on it. Always appreciate input from those on this forum.

 

[BKVP]

Wood stove in a garage....here it comes!

 

[Governorjohn]

I have a similar one but want to ask about the intake vent.
The lid that closes on top of the intake, do you have a supply point for that felt like gasket?
On mine it's like a 2" x 6"~ cottony (probably asbestos) filliment pad. Nothing like the door gasket

 

[begreen]

I would cut the gasket out of a thin mat of ceramic fiber and would use a thin coat of RTV silicone to adhere it. This can be found on Amazon. Search for:

Lynn Manufacturing High Temperature Gasket Paper, Superwool, 2100F Rated, 1/8" Thick x 7" x 10", for Wood Stove, Pellet Stove, Boiler, Furnaces, Kiln, Forge, 2260J​

 

[Warpigs446]

New to the forum, after reading this thread, I think my question falls in here. Have an Earth stove the one with the ceramic flower on the front. I have attached photos, my question concerns the air vent box on the back, the previous owner of the house had a roof leak and the bottom of the box on both sides has rusted out somewhat. Is there a way to repair this? If so recommendations? Thanks

 

[Blazzinghot]

I have blown this picture up you sent and it appears to be surface rust which not affect the working of the air intake or cause an air leak from the fire box. But you might take a wire brush and clean it and see how deep the rust spot is. It if goes through the metal then it would not hurt to have it welded. But if only surface rust then wire brush and paint it with heat resistant paint.

 

[Warpigs446]

I have blown this picture up you sent and it appears to be surface rust which not affect the working of the air intake or cause an air leak from the fire box. But you might take a wire brush and clean it and see how deep the rust spot is. It if goes through the metal then it would not hurt to have it welded. But if only surface rust then wire brush and paint it with heat resistant paint.

What you’re seeing is fire from the fire box, I should have said that in the original post. Is this part of the vent steel or cast iron? If it’s cast iron can it be welded? And recommendations on type of business that can do cast iron welding? Or if it’s steel could this be something I can use a TIG welder on after cleaning up?

 

[Blazzinghot]

Well thanks for the clarification I thought it could be was not sure as it was hard to tell from the picture. If that is the case yes, have it welded as it is not cast iron but steel. Have you ever thought about upgrading your stove? Those older Earth Stoves can eat allot of wood compared to the newer EPA rated wood stoves. Most people I have sold wood stoves to are not aware that they could get a good used wood stove that has secondary burners or catalytic burners. There is plenty of information on this site about how these types of stoves work and save on wood.

 

[AK907]

I am having trouble with my Earth Stove. When I first started using it couple months back everything was great, was producing great heat and was long lasting. I had the air intake on LOW consistently during this time. But a couple weeks back I was getting smoke coming at me when I opened the door, I had a family member come and I did have build up in the stove and pipe and we burned it HOT for about 10-15 minutes. The smoke went from super thick and he burnt it until the smoke was not visible. Now the last couple of days I have flames BURSTING out at me when I crack open the door to check the fire. The flames are getting shot out and is now a saftey hazard and I do not feel comfortable burning until I get a better understanding of the stove. When I put wood in in the morning I let it burn till it is hot, but maybe I am not letting it burn hot long enough. I have read the manual in a quick manner but plan on reading it all the way through.

While the fire is warming up I have the air intake near the HIGH. When I close it up I do not switch it for a couple minutes to medium, then on to low when I go to bed. I am not getting hardly any heat out of it anymore and the wood is not burning through the night anymore, or producing very little heat but have hot coals with the wood burnt but no flames. I am also confused about the back flapper as well, of whether it should be open or shut? I didn't even notice this feature until the family member noticed that it was a flap with a metal hook on the back. Also the gold colored knob does that do anything? I did notice it rotates, is this a air intake option or just a knob? I do want to point out that i am burning seasoned Red Fir

 

[begreen]

What model Earth Stove is this? If it's a model 100, read the whole thread, in particular the posting by Coaly.

Have the flue system and chimney cap checked immediately by a reputable professional. This could be a dangerous situation. The issue may not be with the stove.